Drum printer for recording blood pressure



Aug. 6, 1968 H. B. WHITMORE DRUM PRINTER FOR RECORDING BLOOD PRESSURE Filed June 13, 1967 m ol INVENTOR. B. WHITMO RE ATTORNEYS United States Patent 3,396,405 DRUM PRINTER FOR RECORDING BLOOD PRESSURE Henry B. Whitmore, Rte. 5, Box 369, San Antonio, Tex. 78211 Filed June 13, 1967, Ser. No. 646,160 4 Claims. (Cl. 346-72) ABSTRACT OF THE DISCLOSURE Blood pressure pulse operates a bellows to rock a bell crank to rotate a drum which carries raised digits. A solenoid is also pulse operated to slam a hammer against the advanced numeral causing a numeric record of blood pressure to be printed. The solenoid-return-spring operates ratchet and pawl to advance printing strip to new position.

The present invention relates to a direct digital pressure recorder, and more particularly, to an improved recording device having wide clinical application for numerical recording of blood pressure of human subjects. It is solenoid and pulse pressure operated.

The object of the invention is the provision of a device which makes a quantitative record of blood pressure pulse in printed digits and, therefore, does not require a continuously moving paper as is required in presently known graphic recording methods.

A further object of the invention is the provision of a pressure actuated recording device, capable of miniaturization, which is bellows and solenoid operated and makes an instant and permanent printed record of blood pressure in numerical digits.

A further object of the invention is a unique device which makes the record above noted at the instant the blood pressure pulse is received.

It is a still further object of the invention to provide a device which is economical to produce and utilizes conventional, currently available components that lend themselves to standard manufacturing techniques.

These and other advantages, features and objects of the invention will become more apparent from the following description taken in connection with the illustrative embodiment in the accompanying drawings, wherein:

FIGURE 1 is a side elevational view of the device with printing rib'bon removed and parts omitted for clarity; and

FIGURE 2 is a top plan view showing portions of the paper roller broken away.

Referring more in detail to the drawings wherein like numerals refer to the same parts in all figures:

The device is shown mounted on a base 10. An inlet port 12 transfers pressure from the pressure source, which may be a blood pressure cuif (not shown) attached to and receiving pulse information from a patient. The inlet port 12 leads into a bellows 14. The bellows 14 has pivotal attachment at each of its extremities. The outer end is a fixed position pivot 16 attached to the post 18. The inner end is pivoted at 20 to the offset portion of a bell crank 22 which rocks about the fixed pivot 24 on the pivot post 26. A dial cord 28 provided with spring tension at 30 is attached at its ends to the ends of the bell crank 22. The dial cord 28 is drawn around a drum or pulley on the hub of wheel 34 on post 32 to rotate the recorder wheel 34 about the post 32. The recorder wheel 34 has raised reversed digits for printing on a permanent record tape or printing paper 36 reeling from a spool 38. When the bel- "ice lows 14 expands or contracts, responsive to increased or decreased pulse pressure, the bell crank 22 moves the recorder wheel 34 proportionately, and the digits are advanced or diminished in proportion to the increase or decrease in pressure.

A continuous carbon ribbon 39 is threaded between the recorder wheel 34 and a hammer 40 and around a pulley or spool 41 and a tension roller 42. The posts 43 and 45, each provided with a tension spring, provide the fixed pivots for the rollers 41 and 42. The ribbon 39 is held spaced from the drum 34 by a suitable shield or ribbon spacer 35. A remotely positioned pulse sensor having amplifying means therewith provides a signal which triggers a relay (not shown) actuating the solenoid 44 causing it to slam forward driving the printing hammer 40 against the raised digits to print on the recording paper 36. The recording paper 36 is drawn around the paper roller 46 and is advanced when the solenoid-return-spring 48 returns the solenoid to open position. The advancing pawl 50 moves forward and engages the ratchet wheel 52 causing the recording paper to be moved forward one space to a position for the next printing. The holding pawl 54 prevents the ratchet wheel 52' from backing up.

Although the invention has been described with reference to a particular embodiment, it will be understood to those skilled in the art that the invention is capable of a variety of alternative embodiments within the spirit and scope of the appended claims.

I claim:

1. A blood pressure pulse actuated device for making an instantaneous numeric and continuing blood pressure record, said device comprising, a blood pressure pulse actuated bellows, drum means carrying raised numeric legends, means responsive to pressure applied to said bellows for moving said drum to a position where the numeric legend on said drum is equal to the blood pres-sure applied to said bellows, printing paper and a carbon, means for positioning said printing paper and said carbon at the numeric legend reached on said drum, a pulse pressure actuated solenoid, a hammer operated by said solenoid to strike said numeral thereby making a permanent record on said paper of the blood pressure quantity operating said bellows, means for returning said solenoid and advancing said printing paper.

2. A unit device as claimed in claim 1 wherein the pulse actuating said solenoid is derived from the same source that moves said drum means.

3. A device as claimed in claim 1 wherein said means for moving said drum comprises a bell crank, an off center pivot on said bell crank attached to said bellows, a dial cord attached at its ends to the ends of said bell crank and drawn around the pivot of said drum in operating enlgagement with said pivot to rotate said drum when said bell crank is rocked.

4. A device as claimed in claim -1 wherein said means for positioning said printing paper comprises a roller for advancing said printing paper from a paper retainer, ratchet and pawl means for rotating said roller, said ratchet and pawl means being operated by said means for returning said solenoid.

References Cited UNITED STATES PATENTS 2/1944 Damron 128-205 9/1961 Gross 34633 

